The usage of UAVs is growing steadily. Mission spectrum is wide and keeps widening, a typical list of missions includes: reconnaissance, military targeting and attack, fire control, and parcel delivery. Currently commercial UAVs require special wireless links to control their flight, each such link may not be geographically sufficient to cover the entire flight path, rather, it provides for a limited section of the path. Typically only a few miles are supported by the link, usually requiring line of sight to the UAV.
While the UAV typically communicates with a wireless ground stations, the human controller is connected to ground stations via a ground network. If the ground station is part of a nationwide system of control stations that coordinate with each other, there is a possibility of a smooth handover of UAV from one ground station to next. An alternative scenario is that of a controller directly communicating with the UAV via a wireless link.
An issue associated with UAV flight control, is the lack or lesser interaction of these aerial vehicles with the general flight control. The weight of UAVs is often less than 25 kgs, and for this and various other reasons their tracking by many radar system is not facilitated. This not only indicates a lack of possibility to control flight using common tracking systems but the hazard that such vehicles pose to civilian, military air traffic, other UAVs and objects on the ground through actual collision or otherwise intervention in flight courses.